"I'm well aware that the council has spent three years looking at this issue and it's very generous of them to extend it another six months and so hopefully as we're coming from an alternative source we can look at new forms of funding that may be suitable," Ms Smith said.

Newcastle councillor Nuatali Nelmes is hopeful the National Trust will agree to take over management of the site.

"They've done a very good job looking after the lock-up site and maintaining its heritage value and the argument for us here is it's a working class heritage artefact that needs to be maintained," Cr Nelmes said.